Lift truck



Aug. l, 1939.

A. M. BARRETT LIFT TRUCK Filed July 6, 1956s 2 Sheets-Sheet l sg l v l y rjarfe. fw/147mb;

Aug. 1, 1939.

A. M. BARRETT LIFT TRUCK Filed ,Jul 6, 1936 2 sheets-sheet 2 Patented Aug. 1, 1939 UNITED STATES LIFT TRUCK Arthur M. Barrett, Winnetka, Ill., assignor to Barrett-Cravens Company, Chicago, Ill., a. corporation of Illinois `Application July 6, 1936, Serial No. 89,036

15 Claims.

The present invention contemplates certain improvements in construction and operation of lift trucks of the general type employing a wheeled lower frame supporting an upper frame adapted to be raised and lowered with respect thereto, the upper frame being movable, in lowered position, under platforms or the like, and being then raised to support the platform for transportation by the truck.

In the main, the present invention is directed to certain improvements in the means for raising the upper platform and holding the same in raised position, and in the means for controlling the lowering of the platform when it is desired to discharge the load.

One object of the present invention is the provision of improved lifting means including a ratchet and pawl connection, whereby oscillation of the steering handle results in imparting a jacking or lifting force to the upper frame to raise the same into its upper position. In this connection, I have provided improved means for connecting the operating crank with the steering handle, in order that the cranking movement may be produced with the steering handle in any steering position. In addition, I" have provided an improved ball and socket connection between the ratchet and pawl carriage mechanism and the upper frame, so that the angularity'introduced in the ratchet shaft due to the forward and upward movement of the frame will not produce binding or shackling of the lifting mechamsm.

Another advantage of the present invention is the provision of such swiveling connection whereby the oscillation of the handle results in reciprocating movement of a ratchet with respect to a pawl normally pressed into engagement therewith, so that regardless of the angularity of the oscillating handle, the same straight line reciprocating force will be imparted to the ratchet shaft.

Another feature of the present invention is the provision of release means for accommodating lowering of the platform supporting frame. This essentially comprises a mechanism operated preferably by the foot of the operator, which first disengages the ratchet and pawl connection, and then, while maintaining this ratchet and pawl connection disengaged, operates to release the holding check which normally supports the platform in raised position. In disengaging the ratchet and pawl connection, I preferably provide a camming member which moves the pawl into inoperative position, and which is sovconstructed-that asvthe pawl moves angularly due to the factthat it is supported on Vthe upper frame, the cam surface will maintain it in inoperative position as long as the releasing mechanism is energized. Also, I preferably provide a mechanism such that during the rst part of its Voperating movement, which releases the pawl and ratchet engagement, no release of the holding or locking means is effected, whereby it is assured that the ratchet and pawl connection -will be released prior to release of the holding mechanism.

Another feature of the present invention of distinct advantage is the provision of a separate foot operated member for effecting disengagement of the pawl from the ratchet shaft without in any manner affecting the holding effect of the locking means. This is of distinct advantage in situations where the operator lifts the upper frame with only two or three strokes of the steering handle, and finds that no further lifting force is required in order to transport the load. However, inasmuch as the draft handle, which is .used for pulling the load, is also oscillatable to lift the frame, every time any motion of the handle is; made the ratchet will be actuated. It is of distinct advantage to have vthe ratchet and pawl connectiondisengaged ,during the transportation of the load by the truck, and for this rpurpose a separate means 'is provided for actuating the .camming member to disengage the pawl while not in any manner affecting the support of the load by the holding check means.

Still another feature of the fpresent invention is the provision of a novel type of hydraulic check for holding the upper frame in any raised position,rand for preventing its lowering except after disengagement of the ratchet and pawl connection which effects raising of the frame.y Itis particularly advantageous, in the present con-` struction, to provide such a hydraulic check ywhich is so yconnected to react between the upper and prevents undue stressing of the supporting frame or of the mechanism.

Other objects and advantages of the present invention will appear more fully from the following detailed description, which, taken in conjunction with the accompanying drawings, will disclose to those skilled in the art the particular construction and operation of a preferred form of the present invention.

In the drawings:

Figure 1 is a side elevational View of a lift truck embodying the features of the present invention;

Figure 2 is a top plan View showing details of the modified construction;

Figure 3 is a more or less diagrammatic view of the raising and releasing means in one of its operating positions; v

Figure 4 is an enlarged view of the mechanism shown in Figure 3, illustrated in a slightly different operating position;

Figure 5 is a side elevational view, partly in section, of the hydraulic check mechanism for locking the lifting frame in its raised position; and

Figure 6 is a sectional view through the control valve of the mechanism shown in Figure 5.

Referring now in detail to the drawings, in Figures 1 and 2Y I have disclosed in general the arrangement of the constituent partsV of the present invention with respect to a lift truck of more or less conventional design. The lift truck essentially comprises a .lower supporting frame 5, having at its rear end suitable journals for supporting a rear axle shaft 6. upon which are mounted the rear supporting wheels 'I. Secured to the axle 6 is a suitable crank member 8, having bearing engagement within the angle member 9 extending transversely across the upper or lifting frame, indicated generally at lil, and comprising the side members I2 extending substantially parallel to the side members [3 of the lower frame. At the forward end, the side members I3 of the lower frame 5 are adaptedk to provide pivotal support as indicated at I4, for link members I5 connected to the forward end of the side members I2 of the upper or lifting frame I0. A suitable crosshead I6, which constitutes a part ofthe lower frame structure, extends between the forward ends oi. the side frame members I3 and provides` a pedestal mounting for a shaft kextending through the bearing plate I8 and having a yokeat the` lower end upon which is pivotally mounted thesteering wheel I9.

The bearing plate I8 is providedwith an upwardly extending portion 29 terminating in spaced arms 22 forming a pivotal support for a pin 23 upon which is mounted the operating handle and steering handle 24. This handle is mounted for pivotal movement about the pin`23 to be oscillated in a generally fore and aft direction. However, the handle 24 `is alsoadapted to swing the supporting bracket 2U and bearing plate i8 in a pivotal direction about the pedestal I6 in order to effect steering movement of the wheel I9.

The arms 22 also provide means therebetween, supported on the pivot 23, for the pivotal mounting of the crank 25, which crank is provided at its upper end with a lip portion 26 engaged by the lip portion 21 of the hook member 28 pivotally mounted, as indicated at 29, on the handle 24. The hook member 28,1ocks the crank v25 for conjoint oscillating movement with the handle 24, but is releasable when it is` desired to lower the handle 24` for draft purposes. a k

The opposite end of the crank 25 is provided with a cup-shaped end portion 3,9, forming a ball and socket joint with the ball member v32 disposed therein. A suitable bolt 33 holds the ball member in the socket 30, and at its opposite end is connected to a second ball member 34 secured in the cup or socket portion 35 of a crank 36. This provides a pivotal swiveling connection between the cranks 25 and 36, so that regardless of the angular movement of the bearing plate 20 and the steering handle 24, any vertical oscillation of the handle in any fore and aft or laterally disposed position will produce rocking movement of the crank 36 about its pivotal support 3'I carried by the outer ends of the arms 33 preferably formed integral with the crosshead I6 and extending rearwardly and upwardly therefrom.

The opposite end of the crank 36,v as more clearly shown in Figures 3 and 4, is provided with a journal portion 39, forming a support for the pivot pin 40 which secures the end of the ratchet shaft 42 for pivotal connection with the portion 39 of the crank 36. The ratchet shaft 42 is provided with the ratchet surface 43 along one edge thereof, and the free end of the ratchet shaft 42 is adapted to extend through the pawl carriage 44 which has the extending arms 45 forming supporting means for the pivot pin 46 upon which the pawl 4l is pivotally mounted. The projecting end of the pawl 41 is provided with a camming oiset 48, which is engaged by one end of the spring member 49 carried by the pin 46, and normally is urged in a counterclockwise direction to force the toothed end 50 of the pawl into engagement withthe ratchet surfacey 43 of the ratchet shaft 42. The pawl carriage 44 is mounted for swiveling movement with respect to the platform or lifting frame I9, this frame being provided with the angle member 52 extending transversely thereacross at the forward end thereof to form a load or platform stop, and being provided with the reenforcing structural members 53 welded to the under surface thereof and carrying the casting 54 having transversely spaced socket portions 55 formed therein. The pawl carriage 44 has corresponding ball members 56 formed integral therewith, which are engaged in the socket portion 55 of the casting 54, so that the pawl carriage 44 is swivelly connected by the double ball and socket connection tothe upper lifting frame through the structural member 53 and the platform' stop 52.

This` is 'of distinct advantage in that as the lifting frame is moved upwardly and forwardly into raised position, the angularity of the ratchet shaft 42 with respect thereto changes, since the outer end of the ratchet shaft 42 is mounted on a pivot located by means of the arms 38 and the55 corresponding pivot 31.' of the crank 36. Without such a swivelling connection, binding or shackling of the ratchet shaft with respect tothe pawl carriage might be occasioned.

In the operation of the structure thus. far described, when the handle 24V is oscillated in a fore and aft direction, regardless of its angular steering position, it imparts a corresponding rocking movement te the crank 36 through the crank 25. This results in a reciprocatory movement of the journal portion 39 of the crank 36, resulting in reciprocation of the ratchet shaft 42 with respect to the pawl carriage 44. As a result, the ratchet 43 is first reciprocated axially downwardly through the carriage 44 ratcheting past the pawl 41 and is then moved upwardly with respect thereto. Its upward movement results in locking engagement with, the toothed portion 50 of the pawl 4l, thereby exerting a lifting force on the upper frame I0, and due to the link connection of v"Z5 this frame through the members 8 and I5, results in a forward and upward movement about the pivots I4 and 8 as centers.

Considering now Figures l and 2 in connection with Figure 5, the lower frame has, extended transversely between the side members I3 thereof, the supporting member E9 which comprises a fabricated structure of substantially right angular shape, as shown in detail in Figure 2. This member 99 is disposed at a slight angle with respect to the horizontal plane of the frame 5and is provided at the forward surface of its vertically extending portion with a ball member 62 adapted to engage in a spherically shaped recess 63 formed in a supporting plate 64 carried by the rear end of a hydraulic check cylinder indicated generally at 65. The cylinder itself comprises the cylindrical portion 65 and the enlarged reservoir portion 69 at the forward end thereof. The rear end of the cylinder portion 65 is provided with outwardly extending flanged portions 91 carrying bolts 68 adapted to extend through the vertical portion of the bracket 69 and to have resilient mounting in enlarged openings therein, as indicated generally at 69.

Disposed within the cylinder 65 is the piston member 79, having the coaxially extending piston rod T2 projecting outwardly through the packing gland member, indicated generally at 73. The outer projecting end of the piston rod 'I2 is provided with suitable ball and socket locking engagement, as indicated at '|4, in a downwardly extending flange 'I5 forming a part of the fabricated structure 53 disposed beneath the platform stop 52.

The reservoir portion 66 of the hydraulic check means is provided with an inlet opening suitably closed by the closure cap 16, and also provided with a screen 'il for filtering the liquid, such as Oil or the like, which lls the interior of the reservoir S9.

In the operation of the hydraulic check, as the upper frame moves upwardly and forwardly, the platform stop 52 and the flange I5 have corresponding upward and forward movement. As a result, due to the swivelling connection 74, the piston rod 'I2 is moved axially outwardly of the cylinder 65, moving the piston I9 to the left, as viewed in Figure 2. This results in vpressure being applied to the liquid at the left hand side of the piston le, and this liquid is bypassed through the piston by means of the ball check valve 18, the passageway 19, and the second ball check Valve 89, to the rear or trailing side of the piston i9. The ball check valves I8 and 89 are normally spring-pressed into closed position,but open upon movement of the piston to the left to provide communication between the interior chamber 92 of the cylinder 65 at the left hand side of the piston 'I9 and the cylinder at the right hand side of the piston "I9, As a result of this displacement of liquid through the piston, the piston moves with the upper frame, and the entire cylinder 65 swivels about the ball and socket connection B2, 63 to assume an angular position determined by the forward and upward movement of the lifting frame I9.

It will be apparent that due to the fact that liquid lls the cylinder at the right hand side of the piston as the piston moves to the left, any reverse movement of the piston 'I9 is prevented, and thus the frame I9 is held in any position to which it may be raised by oscillation of the handle 24.

In order to provide for lowering of the frame I9 When it is desired to dispose of the load, a control valve indicated generally at 99 is provided. This control valve, as indicated in detail in Figure 6, comprises a shaft element 9| which has a reduced threaded portion 92 threaded internally of the valve cage member 93, which cage member in turn is threaded at 94 into a laterally extending offset 95 of the cylinder 65. The shaft 99, at its inner end, is provided with the tapered valve portion 96 adapted to have seating engagement with the valve seat 91 formed in the valve cage member. The reduced portion of the shaft 99 between the valve portion 96 and the threaded portion 92 is of smaller diameter than the passageway 98 extending through the valve cage member, and as a consequence when the shaft 99 is unthreaded to unseat the portion 96 from the valve seat 9i, fluid within the cylinder 82 can pass outwardly through the passageway 98 and the normally extending passageway 99 into the annular opening |99 disposed about the valve cage member and communicating through the side passageway |92 with the main reservoir chamber 99. The shaft 99 is sealed against leakage by means of the packing E93 retained in sealing engagement with the lateral surface thereof by the spring |94, while the valve cage member 93 is sealed by the packing E95 disposed in an enlarged annular recess thereof and compressed into position by the spring |96.

The outer projecting end of the shaft 99 is clamped between opposite arms of a suitable cranking member |97, which crank member is provided with an offset projecting pin |98 adapted to be engaged by the end |99 of a control lever I I9. Suitable stop means |I2 is provided to prevent the forked end |99 of the lever H9 from slipping laterally oi of the pin |98.

At its opposite end, the control lever member H9 is pivotally mounted, as indicated at H3, upon the lever |14 pivotally mounted at its lower end on the pin |I5 carried by a forwardly extending ear ||6 of the cross head I6.

The upper end of the leverV I I4 carries a pivot pin I I1 which establishes pivotal connection with the lower or forward end of a link I I9. The lever I I4 and link II9 constitute the two parts of a toggle linkage, of which the pivot IIT is the knuckle joint. Forward and rearward throw is imparted to vthis knuckle joint I Il by an actuating link I I8 which has its rear end connected with said knuckle pin. The actuating link H8 at its opposite end, is connected through the pivot pin |29 with the lower end |22 of a` treadle member |23 mounted for independent rotation upon the shaft |24 extending transversely across the crosshead I6 and supported at the inner ends of the extending arms 38. On the upper side of the shaft |24 and formed as a part of the member |23 is a rearwardly extending substantially hori- Zontal treadle portion |25, adapted for actuating the member I 23 -to rotate the `same about the shaft |24, and also formed as a part of the member I23'a return treadle portion I 26 adapted `to be engaged by the operator for returning the mechanism to normal position. Y

Mounted on the shaft |24 inwardly or the treadle member |23 is a cammingmember indicated generally at |39, which is keyed to the shaft for conjoint rotation therewith, and which has camming surface |32 formed thereon and adapted to engage the offset cam roller 48 o-f the pawl member 41.

Intermediate its ends, the member |39 is provided with a journal portion supporting a pivot 7,5

pin |33 to which is pivoted the upper end of the upper toggle link ||9.

The shaft |24, which extends transversely across the crosshead I6 and is supported for rotation in the lower and inner ends of the arms 38, has mounted on its opposite end the hub portion |35 of a second auxiliary treadle member |35, the treadle member |36 being secured rigidly to the shaft |24 whereby upon actuation thereof the shaft is rotated. When the treadle member |35 is moved downwardly, the shaft |24 rotates in a counterclockwise direction, and thus produces counterclockwise rotation of the member |35. This moves the camming surface |32 of the member |30 upwardly into engagement with the roller 4E, moving the pawl 41 in a clockwise direction out of engagement with the ratchet shaft 42. As a result, the ratchet shaft is disengaged, and the shaft and carriage are free to have relative movement. However, it must be understood that even with disengagement of the pawl 41, the upper lifting frame will be maintained in position due to the holding check provided by the hydraulic piston and cylinder arrangement previously described.

It sometimes happens that an operator finds that he can lift the load upon the lifting frame I with only one or two strokes of the handle 24, and consequently does not impart full lifting movement to the frame I0. As a result, any further oscillation of the handle 24 during hauling of the truck may result in further raising movement of the lifting frame, which is undesirable. In order to prevent such an occurrence, the operator need merely depress the treadle member |36, thereby rotating the shaft |24 and disengaging the pawl 41 from the ratchet shaft 42. As a result, further oscillation of the handle 24 will not result in imparting any further lifting movement to the lifting frame lil, since the ratchet and pawl connection has been disengaged. The operator may therefore safely oscillate the handle during pulling of the truck to the desired position, and may then actuate the mechanism controlled by the treadle member |23 to secure release of the hydraulic holding means for lowering the lifting frame.

The oscillation of the mechanism shown in details in Figures 1, 3 and 4, which controls the lowering of the lifting frame, is adapted to produce two separate and distinct results during its movement through its operating range of position. Briefly, when the treadle member |25 is depressed, it produces counterclockwise rotation of this member about the shaft E24. This results in angular movement of the end |22 of the treadle member, producing a thrust through actuating link H8 upon the knuckle pivot ||1 of the toggle links ||4 and H9, and thereby producing a lifting effort on the member |50 to raise the cam surface |32 thereof into engagement with the roller 48 to disengage the pawl 41 from the ratchet shaft 42. This occurs immediately upon initial depression of the treadle member |25. However, during this first part of the downward movement of the treadle |25 the resultant motion of the toggle linkage is practically the same asl that effected by the complete depression of the other treadle |35. Thus, during approximately onehalf of the downward movement of the treadle member, no substantial movement of the check controlling link |||l is accomplished, and disengagement of the pawl is assured prior to any actuation of the release means for the hydraulic check. i

.As the pivot ||1 between the toggle members |14 and ||9 passes through and beyond the dead center relation of the pivots ||5 and |33, a substantial clockwise rotative movement is imparted to the toggle lever H4. This in turn produces a thrust upon the left hand end of the control link Ill, causing it to move to the right and to rotate the crank |01 in a counterclockwise direction. Rotation of the crank in this direction unthreads the valve member Sii from the valve seat $31, resulting in release of the liquid compressed on the right hand side of the piston 1i), allowing the piston to return to its normal position and lowering the frame l0. While the hydraulic holding means is constructed to lower the load at a relatively slow, safe speed, the operator is also enabled to reduce the lowering speed or to stop and start the lowering, if desired, by alternately depressing the treadle members |26 and |25.

It is therefore believed apparent that I have provided a lift truck design in which the upper frame can be raised into load supporting position independently of the angle at which the steering handle is disposed, and that oscillation of the steering handle about its horizontal pivot will result in jacking of the frame into raised position due to the pulling connection between the cranks. Also, it is apparent that by the provision of the hydraulic check which is expanded upon movement from the frame, the upper frame can be maintained in any raised position automatically, without the setting of any holding up means by the operator.

By the provision of the improved control mechanism for controlling the lo-wering of the frame, it is possible to use the steering handle for draft purposes without effecting the position of the upper frame, and it is also possible to disengage the pawl and ratchet connection independently of actuation of the check. It is obvious that the check must be held locked in position at all times that the ratchet and pawl connection is maintained, since otherwise the load on the upper frame would probably result in undue stressing of the ratchet and pawl connection. Thus, the particular mechanism is peculiarly adapted for effecting the proper sequence of operation in lowering of the frame without any skilled operation on the part of the operator.

I am aware that various changes both in design and construction of various constituent parts of the present invention can be made without in any manner altering the underlying principles of the present invention, and I therefore do not intend to be limited to the exact features shown and described, but only inso far as dened by the scope and spirit of the appended claims.

I claim:

1 In a lift truck of the class described having a lower frame including, a cross head at one end thereof, an upper frame, means connecting said frames for upward and forward movement of said upper frame with respect to said lower frame, a steering handle pivotal-ly carried on the cross head, ratchet and pawl means controlled by oscillation of said handle for lifting said upper frame into raised position above said lowei` frame, hydraulic check means for holding said upper frame in raised position, and toggle actuated release means operable during the initial part of its movement to release said pawl means from said ratchet and subsequently operable to release said hydraulic check means while maintaining said pawl in released position.

2.` In combination, a lift truck having a lower frame including a cross head andan upper frame, an operating and steering handle swivelly mounted on said cross head for steering movement and pivotally mounted on a horizontal axis for operative movement, a pawl and ratchet connection between said handle and said upper frame including means providing a swivelling engagement between said handle and said connection whereby oscillation of said handle about said horizontal axis in any steering position raises said upper frame with respect to said lower frame, hydraulic means automatically locking said upper frame in Xed position at any point in its raising movement, and toggle actuated release means for lowering said upper frame comprising means for initially disengaging said pawl and ratchet connection and subsequently releasing said hydraulic locking means while maintaining said pawl and ratchet connection disengaged.

3. In combination, a lift truck comprising a lower frame, an upper frame, means for. raising said upper frame with respect'to s'aid lower frame comprising a reciprocable ratchet barV and a cooperating pawl pivotally mounted on said upper wheel, an upper framev mounted on said lower vframe for upward movement relative thereto, a

steering and lifting handle pivotally mounted on said truck, raising means for said upperfframe comprising a ratchet bar adapted to be vreciprocated by said handle, and a pawl pivotally mounted on said upper frame and cooperating with said ratchet bar, said raising means being operable upon oscillation of said handle in'any steering position for jacking said upper frame upwardly with respect to said lower frame, hydraulic means operable during said jacking to have relative separating movement between said frames andincluding means for locking said upper frame against lowering fromany-raised position, means for lowering said upper frame including means for pivotally swinging said pawl out of engagement with said ratchet bar and means for subsequently effecting restricted release of said locking means to permit lowering of said upper frame.

5. A-lift truck comprising a lower frame, an upper frame adapted to be raised and lowered with respect thereto, a raising handle pivotally mounted for oscillation on said truck, a ratchet adapted to be reciprocated upon oscillation of said handle, a pawl swivelly mounted on said upper frame and operatively engaging said ratchet upon upward movement thereof whereby reciprocation of said ratchet imparts raising movement to said upper frame, means locking said upper frame in raised position independently of said raising means, and means comprising a pivoted cam member operable to. pivotally swing said pawl out of engagement with said ratchet and to maintain said pawl disengaged during lowering movement of said upper frame upon release of said locking means.

6. In a lift truck having means for raising an upper frame and including independent means for locking said frame in raised position, the

center position;

VVa

'combination of means for controlling lowering movement of said upperframe from raised position comprising toggle links and cooperating cam means for initially disengaging the raising means while retaining the locking means in operative position, and means operable upon further movement of said controlling means in the same direction :forfreleasing 'said locking means while retaining said'raisin'g means in disengaged position.

7. In combination, a lift truck comprising a Ylower frame and an upper frame, a steering handle pivotally mounted 'on said truck, a pawl carriage'having ball and socket connection with said .upper frame, a pawl pivotally mounted on said carriage, a ratchet shaft pivotally supported aboveV said lower frame, lever'means connecting said .shaft to .saidhandle including a swivelling ball and socket connection whereby oscillation of said handleproduces reciprocating movement of said -ratchet shaft with respect to said pawl, and means on said .pawl engaging said shaft upon movement irione direction thereof to raise said upper framewith respect-to said lower frame.V

8. In combination, a lift truck comprising an upper frameandalower frame, said upper frame:

being movable vertically with respect to said lowerframe, means .for raising said upper frame including a pawl and ratchet` connection, means for locking said frame in raised position, a

treadle member pivotally supported adjacent one.

end of said lower frame, a pawl-engaging cam pivoted coaxially with saidv treadle member, a toggle connection between-.theextending vends of said. treadle'memberand cam for maintaining .said cam in pawl-releasing position throughout .actuating movement of said pedal member, and meansextending'abetween said toggle connection and said locking means for releasing said locking means when said toggle connection passes over- .-.9`.' In rcom'binatiozn.aV lift ltruck comprising 'an upper4` framers-and a;lower frame, said upper --framelxbeing *movable vertically with respect to said lower frame, means for raising said upperirame including a pawl and 1ratchet connection,. means. for locking said lframeein.,raisednp'osition, a vtreadle member pivotallyls'upported "adjacent one end of said lower-iframe,- apawl-engaging cam pivoted coaXiaIIy with-:said treadler.member, a toggle con-L nection between said cam and a pivot point on said lower frame and actuated by said treadle member for maintaining said cam in pawl-releasing position throughout actuating movement of said pedal member, means extending between said toggle connection and said locking means for releasing said locking means when said toggle connection passes over-center position, and a second treadle member pivotally mounted on said lower frame for moving said cam into pawl-releasing position independently of said iirst treadle member and said toggle connection.

10. In a lift truck having a lower supporting frame including a cross head at one end thereof and an upper frame adapted to be raised and lowered, a platform stop on said upper frame, means secured to said stop including a pair of spaced sockets, a pawl carriage having balls engaged in said sockets providing for rocking of said carriage with respect to said upper frame, a pawl pivotally supported in said carriage, a ratchet shaft adapted for reciprocating movementin said carriage and engaged by said pawl, a supporting member secured on said lower frame, an actuating crank pivotally mounted on said member.v and-having pivotalA connection y at one end with said shaft, a ball; memberiatf the opposite end of said crank; a steering handle swivelled in saidcross head andpivotally mounted for oscillating movement about a-horizontal axis, aY crank actuated by oscillatingimovementiof said handle, and a swivellingconneetion betweensaid last-mentionedcrankand said ball member of said first-mentioned crank-for rocking'said first-mentioned crank to reciprocate saidratchet shaft with respect to said pawl regardless Yof the angular steering. position of .saidhandla 4 .11. A lift truck ,having ai .lower frame, an

,. upper frame, a ratchetsguide having ball `and socket support ,on said upper frame including a pivotally mounted pawl, a ratchet carried by said lower frameand adapted to be reciprocated'in said guide forengagement withsaid pawl to 1 raise said upper. frame,-hydraulic.meansfor locking said frame.in:raised-:positiornxand means operable independentlyof said ratchet forpivoting said pawl out of engagementrwith.saidratchet and for thereafter .releasingfsaid locking means to -eieet lowering of said upper frame.

`12. Raising means-foraxliftxtruck. having a Ylower frame including atcross head andan upper frame, comprising aratchetzguide pivotally supported on said upper. frame `adjacent said cross head,. axpawl: .pivotallwzmountedain :.said` guide,

crank meanspivotallyx supported on said.: cross head and including a ratchettextending through said guide and;freciprocatedathereinmponsoperation of said crankmeanafspring means normally pressing said pawl intoy engagement' with said ratchet. to elect raising movement of said upper frame upon 'alternate .reciprocations 5of, .said ratchet, and separate ymeans :pvotallysupported on said cross .head .for pivoting said `p awl out of engagementwith said ratchet.

13. A lift truck comprising a lowergframehaving across head and-lair upperrframe; a .steering and operatingzi'hahdle pvotedizfom azhorzontal axis on said cross headzandincl'uding acoaxially pivoted..be11.crank,. a.:second dielkcrank pivo-tally supported on saidreross head-inV apositiom offset from said 'first' bell crank, .ball :andfsocketi connectio-n between one :endxofrsaickrst fhellxcrank and one end of saidsecond bellcrank, alratchet pivotally supported atrthe other :endofs'aid-second bell crank, and pawl meansfcarrled fby".` said `upperframeand engaging vsaid ratchet whereby lupon oscillation of. said handle said ratchetk is wreciprocatedrin said pawl means to raise said upper frame.

\ 14. In a lift'truck of the class described, the 5 combination of awmain frame mounted on rear v Wheels and a` laterally steerable'front wheel, a

liftingvframe mounted on said main frame for upward movement-relative thereto, an operating vhandle pivotally mounted on said mainframenl() for vertical'swinging-.movement, and also for lateral swinging movement ,to steer said-front wheel, Vpawland ratchet raising mechanism actuatable by: vertical swinging lmovement of said handle for raising .said lifting frame, hydraulic :.15 means governingsaid lifting frame comprising a cylinder pivotally .connectedrwith said main frame and a piston zin-,saidycylinder pivotally connected with said-:lifting frame.. a bypassf-in v said cylinder :adaptedztorbypass liquid fromonehgo side of said'piston 'totheotheig a valve associatedv with said clyinder extending substantially at right; anglesthereto and goperative tocontrol saidV bypass, threadednmeans'ffor causingyaxial motion-of said valveg'upon-rotationxthereof; a5125 crankon saidyalvezfor rotatinggthe latter, a link arranged totransmit motion-'to'said crank, and control apparatus :operative tcnrelease'said-` pawl and .ratchet mechanism' and; also yoperativeto impart thrusting:motion-:tor said link for actuat- :30

Yfor holdingsaid lifting frame in'elevated position, a cam for ,releasing saidpawl andratchet raising mechanism, togglelinks for. moving. said -cam into operative position, aftrip member for I.. 45

actuatingvsaid toggle links,and-means responsive" to the motion of said-toggle linksz for Ireleasing said holding device.

' ARTHUR MJ. BARRETT. 1.50 

